Search our library of homework questions

Top answers

All subjects

All levels

Which food chain has the highest proportion of energy transfer. Grass -> cow -> human. Grass -> grasshopper -> rat -> snake. Rice -> human

Rice -> human. due to it having the fewest trofic levels (stages in the food chain) with each trofic level energy is lost through heat and movement as well as energy lost due to unabsorbtion in the dig...

Answered by Ryan M. • Biology tutor

3608 Views

How would you synthesise an carboxylic acid just from a primary haloalkane like bromoethane?

Nucleophilic substitution using NaOH to convert haloalkane to primary alcohol. This is a mechanism that you need to know for the exam. Then oxidise the alcohol by refluxing with acidified potassium dichro...

Answered by Ollie W. • Chemistry tutor

4100 Views

Integration

Integration is a simple way of "quickly" adding. In cases where you have a curve under a graph for example a velocity-time graph, the area under the curve will give you the distance. If you know...

Answered by Neal A. • Maths tutor

3712 Views

Mechanics 1: How do you calculate the magnitude of impulse exerted on a particle during a collision of two particles, given their masses and velocities.

Conservation of momentum is the key principle always used in problems of these type. Here, it asks for the impulse, which is a force measured in Newtons, and it is defined as the change in momentum. F=m(v...

Answered by Ina H. • Maths tutor

26301 Views

A curve is described by the equation (x^2)+4xy+(y^2)+27=0. The tangent to the point P, which lies on the curve, is parallel to the x-axis. Given the x-co-ordinate of P is negative, find the co-ordinates of P.

Firstly, implicitly differentiate the function to find dy/dx in terms of y and x: dy=dx = (-x-2y)/(2x+y). Secondly, set this equal to zero to obtain an expression of y in relation to x or vice versa: x=-2...

Answered by Rahul P. • Maths tutor

8104 Views